<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
          div{
              border: 1px solid #ccc;
              width: 400px;
              height: 250px;
              background: radial-gradient(circle , red 30%, #fff 30%);
          }
    </style>
</head>
<body>
    <div></div>
</body>
</html>